This document discusses features of linear, quadratic, and other non-linear functions. Linear functions have the form y=mx+b and are linear, while quadratic functions have the form y=ax^2+bx+c and have a minimum or maximum point. Other non-linear functions may have disconnected curves or sections that are increasing, decreasing, or constant. Key features to notice include intercepts and whether parts of the graph are increasing or decreasing based on the y-values from left to right.